diff --git a/storage/app/query_test.go b/storage/app/query_test.go
index 8c228c7..56ef050 100644
--- a/storage/app/query_test.go
+++ b/storage/app/query_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9
+// +build cgo
 
 package app
 
diff --git a/storage/app/upload_test.go b/storage/app/upload_test.go
index 7260aa1..441cbc6 100644
--- a/storage/app/upload_test.go
+++ b/storage/app/upload_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9
+// +build cgo
 
 package app
 
diff --git a/storage/db/db_test.go b/storage/db/db_test.go
index bbc1d9d..1fa1987 100644
--- a/storage/db/db_test.go
+++ b/storage/db/db_test.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build cgo
+
 package db_test
 
 import (
diff --git a/storage/db/dbtest/dbtest.go b/storage/db/dbtest/dbtest.go
index 8fb0692..ce966ca 100644
--- a/storage/db/dbtest/dbtest.go
+++ b/storage/db/dbtest/dbtest.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9
+// +build cgo
 
 package dbtest
 
diff --git a/storage/db/sqlite3/sqlite3.go b/storage/db/sqlite3/sqlite3.go
index 6efb041..204053b 100644
--- a/storage/db/sqlite3/sqlite3.go
+++ b/storage/db/sqlite3/sqlite3.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9
+// +build cgo
 
 // Package sqlite3 provides the sqlite3 driver for
 // x/perf/storage/db. It must be imported instead of go-sqlite3 to
diff --git a/storage/localperfdata/app.go b/storage/localperfdata/app.go
index 8c34828..fc8eaea 100644
--- a/storage/localperfdata/app.go
+++ b/storage/localperfdata/app.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9
+// +build cgo
 
 // Localperfdata runs an HTTP server for benchmark storage.
 //